The 6442 is a triode for grounded-grid operation. As an oscillator in a suitable cavity it can produce useful output at up to 5 GHz. This particular exhibit was employed as a driver stage in an AN/ARC-52 UHF set. The final power amplifier would have been something like a 4X150A and the modulator would be a pair of 2E26's.

For microwave pulse operation, a 2 KW pulse is possible at 3.5 GHz or a wavelength of about 9